Buggy code:
public class RegistrationController extends ModelMaker { private final Logger logger = LoggerFactory . getLogger ( this . getClass ( ) ) ; public void init ( ClubApplication app ) { post ( "//submitRegistration" , ( request , response ) -> { logger . info ( "Submitting<seq2seq4repair_space>registration" ) ; UserBean bean = mapUser ( request . cookie ( "provider" ) , request ) ; User user = app . getUserManager ( ) . syncUser ( bean ) ; Login . resetCookies ( request , response , user ) ; return null ; } ) ; before ( "//protected//*//*" , ( request , response ) -> { if ( ! ( app . hasPrograms ( ) ) ) { response . redirect ( "//protected//setup" ) ; halt ( ) ; } } ) ; get ( "//protected//:id//family" , ( request , response ) -> { User user = getUser ( request ) ; return new ModelAndView ( toMap ( "regInfo" , app . getProgram ( request . params ( ":id" ) ) . createRegistrationForm ( user ) ) , "family.ftl" ) ; } , new FreeMarkerEngine ( ) ) ; before ( "//protected//:id//family" , ( request , response ) -> { if ( "submit" . equals ( request . queryParams ( "submit" ) ) ) { logger . info ( "Submitting<seq2seq4repair_space>family<seq2seq4repair_space>registration" ) ; RegistrationInformation form = updateForm ( app , request ) ; Family family = form . register ( getUser ( request ) ) ; postRegistrationRedirect ( response , family ) ; halt ( ) ; } } ) ; post ( "//protected//:id//family" , ( request , response ) -> { return updateRegistrationForm ( app , request ) ; } , new FreeMarkerEngine ( ) ) ; get ( "//protected//:id//family//:familyId" , ( request , response ) -> { User user = getUser ( request ) ; String programId = request . params ( ":id" ) ; String familyId = request . params ( ":familyId" ) ; if ( leadsProgram ( user , programId ) ) { return new ModelAndView ( toMap ( "regInfo" , app . getProgram ( programId ) . createRegistrationForm ( familyParent ( app , familyId ) ) ) , "family.ftl" ) ; } response . redirect ( "//protected//my" ) ; halt ( ) ; return null ; } , new FreeMarkerEngine ( ) ) ; before ( "//protected//:id//family//:familyId" , ( request , response ) -> { User user = getUser ( request ) ; String programId = request . params ( ":id" ) ; String familyId = request . params ( ":familyId" ) ; if ( ! ( leadsProgram ( user , programId ) ) ) { response . redirect ( "//protected//my" ) ; halt ( ) ; } else if ( "submit" . equals ( request . queryParams ( "submit" ) ) ) { logger . info ( "Submitting<seq2seq4repair_space>family<seq2seq4repair_space>registration" ) ; Family family = updateForm ( app , request ) . register ( familyParent ( app , familyId ) ) ; <START_BUG> response . redirect ( "//protected//my" ) ; <END_BUG> halt ( ) ; } } ) ; post ( "//protected//:id//family//:familyId" , ( request , response ) -> { return updateRegistrationForm ( app , request ) ; } , new FreeMarkerEngine ( ) ) ; get ( "//protected//:id//newClubber" , ( request , response ) -> { User user = getUser ( request ) ; String programId = request . params ( ":id" ) ; if ( leadsProgram ( user , programId ) ) { Program program = app . getProgram ( programId ) ; RegistrationInformation form = program . updateRegistrationForm ( UtilityMethods . map ( "action" , "child" ) . build ( ) ) ; return new ModelAndView ( toMap ( "regInfo" , form ) , "family.ftl" ) ; } response . redirect ( "//protected//my" ) ; halt ( ) ; return null ; } , new FreeMarkerEngine ( ) ) ; get ( "//protected//:id//newWorker" , ( request , response ) -> { User user = getUser ( request ) ; String programId = request . params ( ":id" ) ; if ( leadsProgram ( user , programId ) ) { return new ModelAndView ( toMap ( "regInfo" , app . getProgram ( programId ) . createRegistrationForm ( ) ) , "family.ftl" ) ; } response . redirect ( "//protected//my" ) ; halt ( ) ; return null ; } , new FreeMarkerEngine ( ) ) ; before ( "//protected//:id//newClubber" , ( request , response ) -> { validateMayCreateNewPeople ( app , request , response ) ; } ) ; post ( "//protected//:id//newClubber" , ( request , response ) -> { return updateRegistrationForm ( app , request ) ; } , new FreeMarkerEngine ( ) ) ; before ( "//protected//:id//newWorker" , ( request , response ) -> { validateMayCreateNewPeople ( app , request , response ) ; } ) ; post ( "//protected//:id//newWorker" , ( request , response ) -> { return updateRegistrationForm ( app , request ) ; } , new FreeMarkerEngine ( ) ) ; } private void validateMayCreateNewPeople ( ClubApplication app , Request request , Response response ) { } private void postRegistrationRedirect ( Response response , Family family ) { } private boolean shouldInvite ( Family family ) { } private RegistrationInformation updateForm ( ClubApplication app , Request request ) { } private ModelAndView updateRegistrationForm ( ClubApplication app , Request request ) { } private Parent familyParent ( ClubApplication app , String familyId ) { } private boolean leadsProgram ( User user , String programId ) { } private UserBean mapUser ( String provider , Request request ) { } }

Fix:
postRegistrationRedirect ( response , family ) ;